Substrate-tensioning means

ABSTRACT

This invention relates to apparatus for coating and drying a fibrous substrate under tension comprising a platform, means at one end of said platform for holding an end of fibrous substrate stationary against said platform under constant pressure, and adjustable tensioning means at the opposite end of said platform for grasping the opposite end of said fibrous substrate for applying and maintaining tension thereon during coating and drying.

UnitedStates Patent Shrenik D. Shrofi Chicago, 111.

June 10, 1969 Sept. 28, 1971 US. Plywood-Champion Paper Inc.

Inventor Appl. No. Filed Patented Assignce SUBSTRATE-TENSIONING MEANS 4Claims, 3 Drawing Figs.

US. Cl 118/33, 1 18/503 Int. Cl B05c11/12 Field of Search 1 18/33,31.5,9,10, 34;73/143, l59;95/109, 12.5; 117/7; 101/4l5.1

References Cited UNITED STATES PATENTS I 754253 19 5 21 "11: ':f.'':f:.::; ..m :L,

' 935,203 9/1909 Harris 101/4151 1,148,883 8/1915 Young 117/7 UX1,386,813 8/1921 Townsend 1 17/7 UX 1,475,248 11/1923 Shafcr 1 18/4251,985,790 12/1934 Maier 118/315 UX 2,568,731 9/1951 Hansen et a1. 73/1593,020,755 2/1962 Murdock, Jr. 73/159 3,190,262 6/1965 Bakish et a1.118/48 3,471,682 10/1969 Hisey et a1. 219/388 Primary Examiner-MorrisKaplan Att0rney-Pennie, Edmonds, Morton, Taylor and Adams ABSTRACT: Thisinvention relates to apparatus for coating and drying a fibroussubstrate under tension comprising a platform, means at one end of saidplatform for holding an end of fibrous substrate stationary against saidplatform under constant pressure, and adjustable tensioning means at theopposite end of said platform for grasping the opposite end of saidfibrous substrate for applying and maintaining tension thereon duringcoating and drying.

SUBSTRATE-TENSIONING MEANS BACKGROUND OF THE INVENTION In commercialcoating operations, fibroussubstrates such as paper and cloth are coatedand dried under tension. Commonly a coating material from a coating pondis continuously added onto a moving paper which is then dried. In suchoperation, it is important to know such conditions as the drying timeand rate, the liquid-holding power under the conditions of actualcoating. Such conditions will, of course, vary dependent upon the typeof paper used as well as the coating material. Attempts to duplicatesuch commercial operation under laboratory conditions for the purpose ofpredetermining such conditions for various paper and other fibroussubstrates prior to commercial operations have not been successful.

Specifically, equipment used heretofore has relied on coating of paperwhile not under tension, and hence the coating in many cases does notpenetrate through the pin holes in the paper, as is the case incommercial operations, and gives erroneous results. Moreover, by notbeing under tension, the paper is not uniformly coated and tends to curland wrinkle. Such curling is doubly undesirable since it also causes thecoating to run and results in a nonuniform coating weight.

SUMMARY OF THE INVENTION Hand coating apparatus has now been found thatinsures the uniform coating of fibrous substrates while under tension soas to make possible for testing purposes the conditions under which suchsubstrates are coated on commercial coaters.

Briefly stated, the present invention comprises apparatus for coatingand drying a fibrous substrate under tension comprising a platform,means at one end of said platform for holding one end of a fibroussubstrate stationary against said platform under constant pressure, andadjustable tensioning means at the opposite end of said platform forgrasping the opposite end of said fibrous substrate and applying andmaintaining the desired degree of tension thereon during coating and 4drying.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric drawing of theapparatus of the instant invention;

FIG. 2 is a partial cross-sectional view through line 22 of FIG. 1; and

FIG. 3 is a broken isometric view of a modification of the instantinvention.

DETAILED DESCRIPTION FIGS. 1 and 2 illustrate the preferred embodimentof the invention. The apparatus comprises a platform 10, clamping meansI! attached to the top of the platform 10 at one end thereof by means ofnuts and bolts 12 and a slotted cylinder 13 rotatably attached to theopposite end of the platform 10 by means of conventional supports (notshown). Tension indicating means 14, preferably a gauge, are operativelyconnected to the slotted cylinder 13 by a conventional gear arrangement(not shown), and a plate 15 is detachably mounted on braces 16 to oneend of the platform 10 adjacent to the slotted cylinder 13 so that theupper surface of the plate 15 is in the same plane as the upper surfaceof the platform.

The clamping means 11 is adjustably attached to the platform 10 by meansof wing nuts and bolts 17 and includes a bar 18 with a flexible backing19 affixed thereto. The slotted cylinder I3 has a slot 20 extendingtherethrough and axially thcrealong almost its entire length. Thecylinder 13 also is provided with knob 21 and ratchet 22, which ratchet22 acts in conjunction with pawl 23 attached to the platform 10 to placetension on a fibrous substrate as hereinafter described.

The operation of the coater comprises placing a sheet of fibroussubstrate, such as paper A, on-the platform 10 underneath the clampingmeans 11. The wing nuts 17 are tightened to securely fasten the paper A'to the platform 10 with the flexible backing 19 insuring that the sheetis held under a substantially uniform pressure. The other end of thesheet A-is placed in slot 20 of the cylinder 13 and the cylinder rotateduntil the gauge 14 indicates that the desired degree of tension is onthe paper. The ratchet 22 and pawl 23 act to lock the cylinder in thisposition. The plate 15 is then attached to the platform 10 and the papercoated as illustrated in FIG. 2. A coating bar 29 moves along the paperin the direction of the arrow to apply coating material 30 to the paper.As the bar 29 sweeps over the end of the sheet of paper the excesscoating material 30 is caught on the plate 15. The paper can be dried byplacing the entire assembly in an even set at the temperature desired,or air dried. Alternatively, the platform 10 may be provided withinternal electric heating coils which act, when turned on, to heat theupper surface of the platform 10 and dry the paper. After drying, thelocking means on the cylinder are released, thereby releasing thetension, and paper is removed from the cylinder 13 by removing the oneend from the slot and by releasing the clamping means. The resultantcoated paper is free of wrinkles and curls and has a smooth, uniformcoating. It is essential that the pressure along the edge of the sheetis constant or the paper will tend to wrinkle when it is being coated.

In an alternate embodiment of the invention, as illustrated in FIG. 3,the clamping means 11 are replaced by a roll of fibrous material 24mounted on an axle 25 rotatably affixed to telescoping legs 26. The axle25 is provided with a friction brake 26 to stop rotation of the axle 25and of the roll at any desired point. The telescoping legs 27 areprovided with set screws 28 which act to lock the legs to the heightdesired.

In operation, the fibrous material is unwound from the roll in thedescription of the apparatus set forth in FIGS. I and 2. After thefibrous material is attached to the cylinder 13, the roll 24 is loweredso that the unwound sheet is pressed firmly against the platform 10. Thetelescoping legs 27 are then locked by means of set screws 28 to firmlykeep the roll in such position and the friction brake 26 is set toprevent further unwinding of the roll. The cylinder 13 is then wound togive the tension desired and the film coated and dried as describedabove.

Modifications of the apparatus are apparent in that any clamping devicemay be used in place of the adjustable clamp shown as long as the paperis held stationary under constant pressure, as, for example, a drop barhinged at one end of the platform with the other end having a swingingcatch for securing it to the platform. In like manner, in lieu ofthreading the paper in the slotted roll, a bar can be attached to theend of the sheet and weights suspended therefrom to give the necessarytension. The plate 15 need not be detachably mounted on the platform,but can be permanently attached by means of hinges and swung out of theway when the substrate is to be mounted onto or removed from theplatform 10. The plate 15 can also be eliminated. While it is mostdesirable that the surface of the platform be flat, it can have a smallcurvature along the coating direction.

As to materials, it is preferable that the platform 10, clamp ing means11, and slotted cylinder 13 be made of metal, although treated woodsresistant to moisture and heat can also be used. The flexible backing ispreferably of rubber, although resilient plastic materials can be used.It will be evident that the tension indicator means can be removablyattached from the roll in order to avoid its damage to exposure to heatin the ovens, if drying is carried out under such conditions. As todimensions, the apparatus will vary in size dependent upon the width ofthe paper to be tested, but it is preferred to keep the apparatus of asize that can be placed in ovens conventionally used to dry coated paperfor testing.

It will be understood that it is intended to cover all changes andmodifications of the disclosure of the invention herein chosen for thepurpose of illustration which do not constitute departures from thespirit and scope of the invention.

What is claimed is:

1. In combination, a fibrous substrate, a platform, first means tofixedly hold an end of said substrate at one end of said platform,second means attached to the other end of said platform and holding theother end of said fibrous substrate for applying and maintaining tensionon said substrate and including locking means therewith,tension-indicating means operatively connected to said second means fordetermining the degree of tension on the fibrous substrate, a platedetachably mounted to the end of the platform adjacent to the fibroussubstrate and said second means and having its upper surface in the sameplane as the upper surface of said platform, and means associated withthe platform for heating the surface thereof.

2. The apparatus of claim 1 wherein said first means is an adjustableclamp and said second means is a slotted cylinder rotatably mounted tosaid platform.

3. The apparatus of claim 1 wherein said first means is a roll offibrous substrate rotatably mounted on an axle supported on telescopiclegs affixed to said platform, said axle being provided with brakingmeans to prevent rotation thereof, and said telescopic legs beingprovided with locking means.

4. Apparatus for coating and drying a fibrous substrate associatedtherewith while said substrate is under tension, comprising a platform,first means to fixedly hold an end of said substrate at one end of saidplatform, second means attached to the other end of said platform andholding the other end of said fibrous substrate for applying andmaintaining tension on said substrate and including locking meanstherewith, tensionindicating means operatively connected to said secondmeans for determining the degree of tension on the fibrous substrate, aplate detachably mounted to the end of the platform adjacent to thefibrous substrate and said second means and having its upper surface inthe same plane as the upper surface of said platform, and meansassociated with the platform for heating the surface thereof.

2. The apparatus of claim 1 wherein said first means is an adjustableclamp and said second means is a slotted cylinder rotatably mounted tosaid platform.
 3. The apparatus of claim 1 wherein said first means is aroll of fibrous substrate rotatably mounted on an axle supported ontelescopic legs affixed to said platform, said axle being provided withbraking means to prevent rotation thereof, and said telescopic legsbeing provided with locking means.
 4. Apparatus for coating and drying afibrous substrate associated therewith while said substrate is undertension, comprising a platform, first means to fixedly hold an end ofsaid substrate at one end of said platform, second means attached to theother end of said platform and holding the other end of said fibroussubstrate for applying and maintaining tension on said substrate andincluding locking means therewith, tension-indicating means operativelyconnected to said second means for determining the degree of tension onthe fibrous substrate, a plate detachably mounted to the end of theplatform adjacent to the fibrous substrate and said second means andhaving its upper surface in the same plane as the upper surface of saidplatform, and means associated with the platform for heating the surfacethereof.